Ejector.



M. LEBLANO.

HECTOR.

APPLICATION FILED SEPT.1Ov 1907.

Patented July 9, 1912 R w in mmfi mw m W n a W? m; n

[TIT

- UNITED STATES PATENT orrro.

MAURICE LEBLANC, OF CROISSY, FRANCE, ASSIGNOR, BY DIRECT AND MESNEASSIGNMENTS, TO SOCIETE ANONYME POUR LEXPLOITATION DES PEOCEDESWESTINGHOUiE-LEBLANC, OF PARIS, FRANCE.

EJECTOB.

Specification of Letters Patent.

Patented July 9, 1912.

Application filed September 10, 1907. Serial No. 392,122.

dent of Croissy, Seine et Oise, F rance,

have invented a new and useful Improvement in Ejectors, is aspecification. This invention relates to ejectors operated by steam orother elastic fluids.

The object of the present invention is to provide an ejector of thattype which shall e both selfas tarting and also capable of maintaining ahigh vacuum. To this end the cross sectional area of the throat of themixing cone is automatically varied in accordance with-the variation inthe vacuum obtained. I In the accompanying drawings Figures 1 and 2amdiagrammatic views indicating in longitudinal section two differentforms of construction of an ordinary ejector. Fig. 3 is a similar viewindicating by way of example one form of construction for carr ing intoefiect an ejector according to t e present invention and Fig. 4 is across section on the line X-Y of Fig. 3.

Referring to Fig. 1 indicating an ordinary ejector the motive fluidsupplied under pressure passes through a nozzle 1 into a chamber 2opposite .a passage 3, called a mixing cone, in which the velocityenergy is-transformed into work of compression. This motive fluidentrains by' friction the fluids which fill the chamber 2 and flow intoit by the inlet 4. These fluids before coming into contact with thestream of motive fluid must pass annular directing nozzles 5 and 6. Themixing cone 3 exhausts into a spac' 7 in which there is aconstantpressure P. Designating the working pressure which it isdesiredto maintain in the chamher 2 by p the form of the mixing coneshould vary as the ratio When the ratio which varies with the nature ofthe fluid is greater than a certain number or mixture of fluids passingthrough the mixing cone and which is 0.58 for steam and 0.51 for air,the mixing cone should be divergent, as shown in Fig. 1.

ratio mixing cone should be at first convergent and then divergent, asshown in F 1g. 2.

l/Vhen the issmaller than this number the of which the following Thejunction 8 of the convergent anddi- .vergent portions of the mixing coneis called the throat.

This throat should be made smaller with respect to the inlet end of the'convergent portion of the mixing cone as the ratio g diminishes.Assuming that in order to maintain a high vacuum in the chamber 2 theejector is constructed as shown in Fig. 2, then on starting the apps--ratus the 'pressure p would be equal to P and during the periodpreceding the establishment of the working condition the ratio 1 Pprised between unity and the value corresponding to the desiredworking'conditions. At the moment of starting the ejector should have aform absolutely different from that which is normally most suitable.Further the ejectorwould refuse to work and the pressure p in thechamber 2 would become greater instead of becoming less than the-'pressure P. Experience shows that an ejector with a convergent'mixingcone followed or not by a divergent mixing cone cannot be started unlessthe convergence is would pass through all the values-comslightthat is tosay-unless the ratio of the throat section to the inlet section of themixing cone is nearly 1. It follows there fore that an ejectorproportioned as it should be for maintaining a high vacuum as soon asworking conditions have been established, cannot be started. Converselyan ejector in which all the parts are incapable of variation but which'is 'ada ted to be self-starting will be unableto profiuoe a highvacuum. Therefore in order that an ejector shall be able to produce ahigh vacuum it is necessary that during the starting. period the sectionof the throat shall gradually diminish in accordance with the increasein the yacuum obtained. It is also necessary, inorder that the effectproduced by the appalatus may be constant, and in order that theapparatus may be self-starting after an accidental derangement that thevariations in the throat section shall be automatically determined bythe variationsv in the vacuum obtained. The crosssectional area of thethroat of a converging mix ng cone may for example be varied by distrting the, walls.

In Figs. .3 and i this method of varying the cross;sectrional,area ofthe throat is illus- Ill erated together and axis trated as applied to amixing cone of tangular section and constant length, the width beinggradually varied from one end to the other of the mixing cone.

Within a casing or receiving chamber 9 having two parallel plane facesat distance 10 the one from the other are arranged two plates having aprofile such as that shown from 11 to 12. These plates are equal inwidth to the distance 10 and are supported against the two plane facesof the casing 9 by means of broad flanges so. as to reduce wear. Theseplates are pivoted at points 13, 13, and it is obvio from the drawingthat by causing these plates-to oscillate about the points 13, 13,the-section of the throat of the mixing cone can be variedet will. l Theends of the plates 'opbposite to the pivoted ends are connected.- ypivoted links 14 -14 ,m rod 15 whi'hreciprocetesimaguide bearin 16 andwhich is provided with a piston woidring in a dashpot 17. B this" meansthe plates 11, 162' are n y 011 oil mixing cone remains unaltered Inorder to renderithe'movemeht of the E two plates 11', militaristic it issuficient to by experience tolls per hold them apart 'bv means ofsprings'18, 18'

attached to opposite walls of the casing 9,- Thus as a vacuum is createdin the chamber 2, the ressure within. themixing cone will fall, wgile'the pressure'outside the cone will remain constant and equal to P.The plates will thentend to close together, but since the tn'sion on thesprings will thus be in creased a state of equilibrium will beestablished-'tmtil "the vacuum isyagain increased, when ,th'eplates willapproach one another still further. The springs will naturally havetobeadiuated, so that as the lates apfluid the proach one another thetension w' increase would to the desired law in order that the thropt ofthe mixing cone may at everymoment correspond in section to the vacuumobtaine (l.'1; v The presence of the dashpot will oppose stile set-tingup of any oscillating movements ofthetwo plates 11, 12, h The etartingof this e'ector haabeen I ectly'automati ji' What-I claim 1s;- j '1. Inan 'ejector' operated by an elastic 'fluid the 1 combination with an"admissl on nozale for' theunotive fluid, of a. receiver chamber, amixing cone located within such chamber, means subjected tofitlttepressure within "the. mixing fcone and'the pressure within the receive?chamber for symmetricallyclosing two'i'walls of the mixing cone, andmeans fon'rprovidi'ng an'increasing resistance to the-pierce of saidressure. 3 2. In an ejectionoperated y an'elastic fluid, the combinationwith an admission; nozzle for the motive fluid, of a receiver chamber, amixing cone located within said chamber and'comprising two oppositestationary walls and two opposite movable walls pivoted at the inlet endof the mixing cone and springs providing a predetermined increasingresistance to the movement of the pivoted walls due to the excess ofpressure in the receiver chamber overt the pressure within the saidmixing cone.

3. In an ejector operated by an elastic fluid, the combination with anadmission nozzle for the motive fluid, of a receiver chamber, a mixingcone located within the said chamber and comprising two oppositestationary walls and two opposite movable spring-retracted walls pivotedat the inlet end of the mixing cone, means for equalizing the movementsof the-said two pivoted walls anda dash-pot for regulating theoscillation of said pivoted walls.

4. In; combination in an ejector, an admis sion nozzle for the motivefluid, a mixing cone, means for directing the fluid to be exhausted intothe mixing cone, and means dependent upon the pressure within said mixmgcone for varying'the cross sectional area of the outlet of the mixingcone in'accordancewit-hthe variation in the vacuum producedby theejector.

5. In an ejector operated by an elastic fluid, the combination with anadmission nozzle for motive fluid of a receiving chamber, a mixing conelocated within said receiv' chamber, means for directing the fluid tobe'exhausted into said cone, and means dependent u on the pressurewithin said receiving cham r and within said mixing cone for varying thecross sectional area of the outlet ofthe mixing cone in accordance withthe variation in the vacuum produced byVethe-ejector. a I

'6. In an ejefioroperatedby an elastic v V a tipn w ith'an admissionnozzle, for thel-findtiye fluid, of a mixing cone," ineans.for'xdirecting the fluid to rexha'usted' into 'the mixing-cone, andmeans dependent upoijf'the pressure within Salli cone gfor; v ethej'convergence of the mixin accordance with the varia tions' 'ur thename of fluid exhausted.

- "7. In an ejector operated by an elastic fluid,

the combination'with an admission nozzle for the motivefluid, a mixingcone, means for directing the fluid to "be exhausted into the cone, andmeans for varying the position of the walls of the mixing'cone so thatrelative roportions' of the mixing cone are varied in accordance withthe variations in the vacuum obtained.

8; In an ejecton'the combination with an admission nozzle for the motivefluid, a mixing cone rovided with two stationary and two mova le Walls,and means for varying the position ofcthe movable walls inac; cordancewith the variation in the vacuum produced by the ejector.

9. In an ejector operated by an elastic fluid, the combination with anadmission nozzle of a mixing cone, means for directing the fluid to beexhausted into the mixing (one, a receiving chamber in which said mixingcone is located and means responsive to the differential of pressurewithin the mixing cone and the receiving chamber for varying the crosssectional area of the mixing cone in accordance with the variations inthe vacuum roduced by the ejector.

10. In an ejector operated by an elastic fluid, the combination with anadmission nozzle for the motive fluid of a mixing cone comprising twoopposite stationary walls and two opposite movable walls and springs forcontrolling the movements of said movable walls.

11. In an ejector operated by an elastic fluid the combination with anadmission nozzle for the motive fluid of a mixing cone provided withmovable walls and yielding means for controlling the motion of saidwalls.

1". In an ejector operated by an elastic fluid, the combination with theadmission nozzle for the motive fluid of a mixing cone provided withmeans for varying the cross sectional area of the outlet of the mixingcone and springs for controlling the opera; tion of said means.

13. In an elastic fluid operated ejector device, an admission nozzle formotive fluid, a mixing cone, and means for automatically varying thecross'sectional area of the out let of the mixing (one in accortlaluewith the varying amounts of fluid exhausted by saiddevico 14. In an astfluid operated ejector device, a motive tluid admission nozzle, a mixingcone, means for directing the fluid to be exhausted into the mixing coneand means for automatically varying the outlet area of the mixing conein accordance with the variation in the vacuum produced by the device.

In testimony whereof I have hereunto subscribed my name this 22nd day ofAugust 1907.

MAURI CE LEBLANC. Witnesses:

DEAN B. Mason, Alumni Dulles.

